opera isn't that bad actually.
It actually all goes to what the mobile device itself can handle and how well it supports opera. I have used opera mini for a long time along with other mobile browsers and never had any problems with it.
Just check around in the settings as has already been suggested above or just try a different mobile browser and see if that works better.
Personally I suggest firefox mobile but everyone has their own personal favorites on what they prefer so your mileage will vary.
